Automatic control device



Dec. 3l, 1929. c. ,A. OTTO 1,742,091

AUTOMATIC CONTROL DEVICE Filed June 5, 1928 2 Sher-Vas-Sheet l aupemtoz v c@& a. OM10 3E": A

Dec. 31, 1929. A, T 1,742,091

AUTOMATIC CONTROL DEVICE Filed June 25, 1928 2 Sheets-Sheet 2 gwuc'ntot Cu/J/ @Okko.

Patented D c. 31, 1929 UNITED STATES PATENT OFFICE CARL A. OTTO, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO JOHNSON SERVICE COMPAN OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN AUTOMATIC CONTROL DEVICE Application filed June 25,

This invention relates to automatic control devices, and particularly to the automatic control of temperature and the like.

The device belongs to that general class in which a valve or similar mechanism is actuated by vapor pressure generated in a bellows or thermostatic cell when an electric heating coil is energized. The energization is controlled by a remote thermostatic or other switch, the exact nature of the controlling switch not being a feature of the invention.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which,' Fig. 1 is a view, somewhat diagrammatic in character, showing the valve, the thermostatic cell and the heater-controlling switch in section and the remaining parts in elevation. The circuits are shown 1n diagram and certain parts are displaced from their normal positions, still maintaining the normal mechanical inter-relation of parts, to make the construction clearer than could be possible otherwise in a single view.

Fig. 2 is a plan view showing the parts as actually arranged to secure greater com pactness.

A valve body is illustrated at 1 and has a seat 2, and bonnet 3. The valve 4, which coacts with the seat 2, is of ordinary form, and

is carried by a stem 5 which is guided in the bonnet 3 and passes through the gland 6 and gland nut ,7. p j

The bonnet 3 is provided with a flange 8 beveled on its lower side to offer a wedging surface to the set screws 9 which clamp the shell or housing 11 in place. No novelty is here claimed forthe parts so far described.

The housing 11 supports on its top a plate 12 having a central, upward extending boss 13. This is provided with a central bore, and, on its lower face. with an annular groove or spring seat 14. The central bore receives a shouldered screw 15, which serves as a guide andlimit stop for the upper head 16 1928. Serial No. 288,165.

sealed together, to form an expansible cham-' her in which is an expansible fluid. The upper head 16 is formed with a deep annular channel 21 to receive the electrical resistance heating unit 22. This is embedded in refractory cement 23. The lower head 18 carries a boss 24 into which the valve stem 5 is screwed. A spring 25, lighter than the spring 17, surrounds the stem 5 and seats at one end against the lower head 18 and at the other end against the gland nut 7.. Mounted on the plate 12 is an ordinary static step-down transformer including the usual core 26. The primary winding terminals are shown at 27 and secondary wind- 1ng terminals at 28. The purpose of this is merely to step down mote thermostatic switch circuit, so that there shall not be destructive arcing at the contacts of this switch.

Also mounted on standards 31, is a magnetic relay comprising the core 32, a winding whose terminals the insulating post 41. y

The armature also carries a lug 42, so arranged that as the armature drops to its lower position it engages and depresses the finger 43 on the mercury-switch clip 44 rocking the entire clip. This clip is pivoted on plate 12 at 45 and is weighted at 46 so thatits normal the voltage for the relowermost position being deplate 12, by means of two I position is with the fin er43 raised. The clip carries also a lug 4 which, when the armature is in its upper position, projects through an opening in the plate 12 nearly to head 16. Thus, if the spring 17 is overpowered and head 16 moves upward, it will tilt clip 44 in the/same direction that the descent of the armature would tilt it.

The clip 44 carries a mercury switch comprising a sealed glass tube 51, two electrodes 52 and-53, and a small quantity of mercury 54, so arranged that the circuit is closed between the electrodes unless the clip be tilted against the action of the weight 46 by finger 43 or lug47. 1

An insulator sup ort 57 is mounted on plate .12 and carries five connectors or binding posts. Of these two, 58 and 59 are those to which the power lines (not shown) are connected. The other three, 61, 62 and 63, are in the secondary circuits, that is, they are energized from the secondary of the transformer.

* tact 66, arm 64, wire 67 The remote control switch is here shown as comprising a thermostatic cont'actor bar 64 and two contacts 65 and 66. Bar 64 is connected by wire 67 with contact 61; contact 65 is connected by wire 68 with contact 62; contact 66 is connected by wire 69 with con tact 63. These connections are of such length as. to allow the remote control switch to be placed at any desired point. p a

The terminals 27 of the primary windings of the transformer are connected respectively to the posts 58 and 59 by wires 71 and 72. There is also a circuit in. parallel with this between posts 58 and 59 by way of wire 73, contacts 52 and 53 of the mercury switch, wire 74, heater coil 22 and wire 7 5. i I

The two terminals 28 of the transformer secondary are connected by wires 76 and 77 with the posts 62' and 63.

The post 63 is connected by wire 78 with contact 39. The post 62 is connected by wire 79 with one terminal 33 of the relay winding, the other terminal,33 being connected b wire 81 and branch 82 with post 61 an contactor 38.

Referring now to Fig. 2, which shows a commercial embodiment in plan, the location of the principal parts, above described, will be readily seen. The arrangement is essentially circular, the magnet armature standing at right angles to the axis of the mercury switch tube, so that lug 42 engages finger 43.. The member 83 is a support or the armored cables that constitute the supply lines leading to posts 58 and 59. o When 64 contacts 66 an energizing circuit is established including the transformer sec ondary from one terminal'28, wire 77, conpost 61, wire 81, one terminal 33, through relay winding to other terminal 33, wire 79, 0st 62 and wire 76 to other terminal 28. The resulting rise of armature 34 establishes a sticker'circuit as follows: transformer secondary wire 77, 'post 63, wire 78, contacts 39 and 38, wires 82, 81, relay winding (via contacts 33) wire 79, post 62, wire 76, back to secondary.

This sticker circuit holds the relay in excited condition until arm 64 contacts 65. Then a short circuit between posts 61 and 62 via 67, 64, 65 and 68 kills the excitation of the relay winding and the armature drops.

\Vhen the relay is excited armature 34 rises and allows the mercury switch to tilt to closed position. Coil 22 heats the fluid in the expansible chamber and its resulting expansion closes valve 4. If excessive pressure is generated spring 17 will yield, allowing plate 16 to move upward and open the mercury switch until the pressure falls sufficiently to relieve spring 17.

Various modifications are possible within the scope of the invention.

\Vhat is claimed is 1. The combination with a controlling device of the type actuated by pressure generated in a motor by an electric heater; of a heater'switch controlling the heater and biased to close; a distant-control switch; a relay controlled thereby; and connections whereby the heater switch may be opened by the relay under the control of the distant switch or by the motor upon the existence of excessive pressure therein. J 2. The combination of a controlled device; a heat energized pressure motor for actuating said device; a spring resisting the force exerted by said motor an electric heater for furnishing heat energy to the motor; a switch controlling said heater, arranged to be opened by said motor when the latter overpowers said spring; a relay motor adapted in one position to open said switch and in another to cause it to close; and a distant switch for causing said relay motor to shift between said positions.

. 3. The combination ofa controlled device;

a heat energized pressure motor for actuating said device; a spring resisting the force exerted bysaid motor; an electric heater for furnishing heat energy to the motor; a switch controlling said heater, arranged to be opened by said motor when the latter overpowers said spring; a relay motor adapted in one position to ,open said switch and in another to cause it to close; and means including a holding circuit closed and opened by the relay, and a switch for causing said relay to shift from one position to the other.

4. The combination of a controlled,device; a heat energized pressure motor connected to actuate said device; yielding means arranged to be overpowered by said motor if the latter develops excess pressure after actuating said device an electrical heater for. furnlshing heat energy to the motor; a switch controlling said heater; means urging said switch in a circuitclosingdirection; means actuated by said motor in overpowering said yielding means and serving to open said switch; a relaymotor shiftable between two positions either to open said switch or to permit it to close; and a switch for causing said relay to shift from one to another of said two positions.

5. The combination of a controlled device; a heat energized pressure motor connected to actuate said device; yielding means arranged to be overpowered by said motor if the latter develops excess pressure after actuating said device; an electrical heater for furnishing heat energy to the motor; a switch controlling said heater; means urging said switch in a two positions.

6. The combination of a controlled device;

- a heat energized pressure motor connected to actuate said device; yielding means arranged to be overpowered by said motor if the latter develops excess pressure after actuating said device; an electrical heater for furnishing heat energy to the motor; a switch controlling said heater; means urging said switch in a closing direction; means actuated by said motor in overpowering said yielding means and serving'to open said switch; a step-down transformer deriving its primary energy ated in a motor by an electric heater; of a heater circuit; means in said circuit for controlling the heater; a distant control-switch; a relay controlled thereby; and connections whereby the heater circuit may be open and closed by the relay under the control of the distant switch and opened by the motorupon the existence of excessive pressure therein.

In testimony whereof I have signed my name to this specification.

CARL A. OTTO.

from the heating circuit; a relay motor in circuit with the secondary of said transformer shiftable between two positions, either to open said switch or to permit it to close; and a switch in circuit with said relay and secondary for causing the relay to shift from one to another of said two positions.

7 The combination of a controlled device; a heat energized pressure motor connected to actuate said device; yielding means arranged to be overpowered by said motor if the latter develops excess pressure after actuating said device; an electrical heater for furnishing heat energy to the motor; a switch controlling said heater; means urging said switch in a closing direction; means actuated by said motor in overpowering said yielding means and serving to open said switch; a step-down transformer deriving its primary energy from the heating circuit; a relay motor in circuit with the secondary of said'transformer and including a holding circuit controlled by the relay motor shift-able between two positions, either to open said switch or to permit it to close; and a switch in circuit with said relay and secondary for causing the relay to shift from' one to another of said two posi tions. 4

8. The combination with a controlling device of the type actuated by pressure gener- 

